


Tides of Change

by VampireRose



Category: Supernatural
Genre: Human Castiel (Supernatural), Hurt Dean Winchester, Hurt/Comfort, M/M, Marine Veterinarian Castiel (Supernatural), Mermaid Dean Winchester, Veterinarian Castiel (Supernatural)
Language: English
Status: In-Progress
Published: 2020-12-05
Updated: 2020-12-05
Packaged: 2021-03-09 20:48:24
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,791
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27882502
Author URL: https://archiveofourown.org/users/VampireRose/pseuds/VampireRose
Summary: Castiel doesn’t exactly believe in fantasy. He knows unicorns aren’t real, that magic only exists in fairy tales, and as fascinating as the old myths are to someone working as a marine veterinarian, there’s no way mermaids exist. Real life half-fish people? That’s ridiculous.Or so he thinks, until one day he ends up finding a wounded creature on the beach close to his home. Now he’s got to prepare himself to accept that the depths of the ocean may hold more than injured marine animals and friendly sea lions named Meg after all.
Relationships: Castiel/Dean Winchester
Comments: 4
Kudos: 13





	Tides of Change

Castiel Novak leads a fairly normal life. He likes to keep mostly to himself and other than with his colleagues and friends at the Marine Life Research and Rescue Center, he doesn’t interact with the people in town much. Dealing with them is just so taxing sometimes, which is why he enjoys working with and helping his animal patients so much. Sure, his job can be demanding and even depressing sometimes as well, when there’s nothing left they can do to help their patient, but even then it doesn’t leave him as exhausted as dealing with the townspeople for a whole day does.

Besides, most of the time they are able to help and there’s nothing more fulfilling for Castiel than watching his charges go on their way after a long and hard recovery. So yes, he vastly prefers his animal patients to the majority of the people in town. 

Still, even though he chose to buy the secluded house down by the beach to live in for that very reason, he doesn’t want to exclude himself completely from the town life, which is why most of the time he walks to town when he visits, instead of driving. It makes him feel somewhat closer to the townspeople and besides, he likes walking and enjoys the view of the beach and the ocean beyond it as he passes by. 

And, speaking of walking, that’s what he was doing right now. Carrying his bag with his lunch ( _ It’s a satchel, Charlie! _ ), he strolls along the beach, looking for a place to sit and eat while he watches the waves. The shore is ever-changing, after all, and he can never count on the same driftwood being there twice. In the vague distance, he spies a washed-up log near some rocks and changes direction to head for it. From what he can see, it appears to be partially in the water, but maybe he can drag it out. When he gets closer, however, a frown crosses his face. Is the log… Shimmering green? A bark sounds near him and he turns his head to see a sea lion hauling itself onto the beach.

“Hi, Meg,” He murmurs and leans to pat the sea lion’s head. He’d rescued her when she was a tiny pup and nursed her back to health. Despite his best efforts, she refused to integrate fully into the wild, so eventually, he gave up and let her hang around. Sometimes she would leave for days on end, but she always returned.

Meg wriggles and goes back to the water, swimming out to where it was deep enough for her to submerge herself, but then her head pops back up and she barks again, this time sounding urgent.

“What is it?” Cas asks. Meg swims away then returns, barking urgently until Cas got the message:  _ follow me _ . This wasn’t uncommon- sometimes Meg would lead him to injured animals that needed help.

He follows the sea lion and realizes that she is leading him to that shimmery green thing lying on the beach. He squints against the breeze coming off the waves and wishes he’d grabbed his glasses - they were transition lenses and would have helped with the reflecting sun. He doesn’t wear his glasses much, something his brothers always needle him about. His diving goggles have special lenses so he can see easier when he is underwater, but it was kind of hard to wear glasses when dealing with frightened, injured, splashing animals. So he doesn’t.

As he gets closer, things get clearer and he notices that the sand is darker near the thing. Blood, Cas thinks, and quickens his pace. It is hard to run on sand, but after years of working for the MLRR he is well-practiced. As he gets closer, his bewilderment grows. He’d never seen anything so green and shimmery and he has no idea what it could be.

He stumbles as his foot catches on his other heel.  _ Clumsy _ , Gabe would laugh, then take a picture with the camera that permanently resides around his neck. “ _ Goes in my ‘Wild Land Animals’ album _ .” Cas quickly regains his balance and shaking off thoughts of his brother, closes the distance. Behind him, he hears Meg barking as though she was laughing and rolls his eyes.

Once he gets to the shimmering thing, things get even more confusing. It looks like a person, but it also has a - Holy  _ shit _ ! Is that a  _ mermaid _ ?

“No, mermaids don’t exist,” Cas mutters under his breath. Though, how could anyone really be sure of that? They are constantly discovering new, fascinating creatures in the sea, so who knows what else lives hidden in its depths?  _ Mermaids,  _ though? Stunned, Castiel scans the mermaid’s body. It’s obvious it’s injured - bleeding from multiple lacerations along its tail and torso, and it seems to be unconscious. Its tail is wrapped in nets. They’re crude, but Cas can see how they would limit its movement. Looking at its face, Cas thinks it might be a male. It has a human torso and it  _ looks _ fairly male. But there are  _ fins _ crawling up his back and spiking out on his tail - this was definitely  _ not _ The Little Mermaid.

“Holy shit,” Castiel breaths. “Holy _shit_ there’s an actual _merman_ on _my_ _beach_. Shit,” He runs his hands through his hair and gazes, wide-eyed, at the bleeding thing in front of him. At Meg’s bark, he shakes himself back to alertness. “Right, right. You can freak out about that later. He’s bleeding.” He looks behind him and can just make out his house around the curve of the beach and huffs out a sigh.

It seems that Cas’ voice rouses the merman because he stirs, moves, just a little, and cracks his eyes open and somehow Cas notices that they’re just as green as his tail.

He says something, so quiet that it’s barely audible and Cas has to crouch down to hear him. 

“What was that?” He whispers. The merman’s eyes flicker to his face and he has that look - the almost-unconscious look Cas’ patients will get just before anesthesia knocks them out. The merman’s about to pass out but it looks like he’s trying to say something.

“Please...” his voice is so hoarse and quiet that Cas almost thinks he’s imagining it and whatever else the merman wants to say is lost as those green eyes - fanfiction green eyes and  _ no _ , Castiel will  _ not _ apologize for reading it - roll into his head and he seems to lose whatever strength was left in his body, falling completely limp.

“Meg, will you stay with him? I’m going to run back and grab a stretcher. I don’t want to just drag him back to the house- Wait-” Cas looks around, making sure that there’s nobody around. “Okay, Meg, stay there.”

He runs back to his house where he drops his lunch bag and goes to find a stretcher and a few ropes to help tie the merman down. Then he throws some medical supplies in a bag so he can tend to some of the worst wounds he saw on the merman right away. Now fully in the mindset of the experienced marine vet, set on doing everything he can to help his patient, he slings the bag full of supplies over his shoulder, grabs the stretcher and makes his way back to where he’d left the merman with Meg. 

He stopped next to the merman and scans his body again, mouth twisting in debate. How was he going to get these nets off? He hates nets for precisely this reason - they harm the marine life and cause them to wash up on the shore because they can’t swim anymore. Thankfully, it’s fairly obvious the merman is still alive. His chest is moving up and down with even breaths. He has no clue how the merman is breathing, though. Even unconscious, he looks like he’s breathing just fine, so he assumes he breathes just like a human. But what surprises Cas when he finds them is, he also has gills. Cas thinks it’s more wounds at first since they’re on his torso and seem to line his ribs, but when he brushes his fingers against them the skin gives. 

“What the hell,” He mutters. It seems almost like the gills closed when the merman got to land so he could breathe normally. He shakes those thoughts away- It’s obvious that the merman is breathing, he can worry about the gills later.

Cas digs the medical scissors out of the bag he brought and carefully sets to cutting the nets. They seem like they’re made of some type of sea plant. Seaweed, perhaps, or kelp.

“Oh, God,” He whispers to himself as he pulls some netting free. There are tiny barbs set in the weave that had dug into the merman’s skin. No wonder the merman is covered in so much blood, he’s got thousands of little pinprick holes in his skin and tears in his fins, the worst tear is in the fin on his lower back, just where the tail starts, which Cas decides to think of as a dorsal. With this knowledge in mind, Cas takes much more care in getting the netting off. He cuts small pieces at a time and, after finding out which direction the barbs are facing, carefully slides them out of the merman’s skin. It takes him at least an hour but he finally manages to get all the nets off the front of the merman, though that still leaves him with the nets on his back.

He ends up rolling the merman on his stomach onto the stretcher. It’s a wide one, the first one he grabbed, so Cas knows he’ll be able to shift the merman to lay on his back when taking him to his house. After another hour, the netting is finally free and lies in a dangerous, barbed heap next to Cas. he knows he can’t leave it there, some other animal could get into it and injure themselves. At least Cas owns this stretch of beach and he made sure to mark it with ‘no trespassing’ signs to keep it private right after he moved in, so there’s no immediate danger of anyone else, let alone children, getting into it and ending up hurt as well. But what to do with it?

He resolves to drag it inland so it doesn’t wash away and pick it up after he’s dealt with the merman’s injuries. That is his top priority right now. 

Decision made, Cas sets to treating the worst of the merman’s wounds. After wiping away as much blood as possible, he bandages what wounds he can right there, leaving the dorsal fin mostly untended. He can’t do anything about that, not right now. But it looks so damaged... Hopefully, the bandages will keep him from bleeding out before Castiel can do more.

That done, Cas tries to somehow figure out how to drag the merman back to his house, where he actually has the medical supplies and space to patch up the merman. He ends up using some of the straps he’d brought to drag the stretcher and is careful to avoid any rocks that washed up on the shore. Thankfully, there aren’t that many as the sandy beach is pretty smooth in general. It’s probably why it was for sale in the first place. Who would want to buy a rocky, uninviting strip of land after all? At least, that’s what Cas thinks. He’d really only bought the additional stretch of property to offer a quiet, people-free environment for his patients to heal and exercise in. The fact that it’s located right in between his house on one side and the MLRRC on the other only cemented his resolve to use his inheritance to buy it along with the property his house is on. From his current position the house is closer, though, and considering the fact that this was a  _ merman _ , Cas thinks it’s a better idea to keep his existence hidden.

Cas drags the stretcher to his house and somehow manages to haul the merman into his dining room, where he lays the creature out on the table and takes stock. The worst of his injuries was the one on his side, the others are numerous but look nowhere near as deep, so that’s the one Castiel focuses on first. Upon closer inspection it looks like it was caused by some kind of weapon and while it does indeed reach deeper than any of the other wounds, it thankfully missed anything vital as far as Cas can tell. He’ll have to stitch that up first, and hopes it won’t be too difficult. He’s not a human doctor, but he treated lots of marine mammals in his time as a marine vet, so he’s fairly positive his supplies will be sufficient. He can always run to the center if he needs more. He grabs his kit, washes his hands, and starts to disinfect the wounds, pulling away strands of seaweed that he hadn’t before.

As he works, he lets himself look over the merman. He is quite attractive, Cas can’t help but notice. He’s lean and muscular and the scales on his tail are a beautiful iridescent green. His hair is cropped short and though it’s dark from dampness, Cas can tell that it’s likely dirty blond or light brown. His face twitches in pain as Castiel works on stitching his wounds, but Cas didn’t want to use an anesthetic and risk causing problems for the merman. He doesn’t know anything about their biology, so what if he has the tolerance of a fish and Cas accidentally overdoses him? What if his tolerance is much higher than a human male’s and any anesthesia Cas uses isn’t enough? There’s just too much Cas doesn’t know, so he’s not going to risk it.

“I’m sorry, I know it hurts and I wish I could do something about it, but I don’t wanna risk making it worse,” he utters softly, not even sure if the merman can even hear, let alone understand him, but the need to say something, to try and offer even the tiniest bit of comfort to his patient, is there all the same.

“I’ll do whatever I can to help you, I promise.” 

Eventually Cas finishes and steps back to take stock of the situation now. His dinner table is covered in blood and he yet again hopes he wasn’t too late to stop the bleeding, after all there is no way for him to tell how long he’s been lying there on the beach, slowly bleeding out. He stops that train of thought and instead focuses on the fact that he did everything he could to help once he did find him. And even though now’s really not the time to think about it very briefly, the thought that his too big dining table is finally of use for something other than awkward Thanksgiving dinner with his family, when he’s forced to host that, pops into his head. 

Now all he can do is wait and hope that the merman will pull through… said merman is now covered in stitches and bandages, even the delicate skin of his numerous fins and Cas feels a pang of guilt when his eyes fall on the pile of scales sitting next to his tools. 

He’d had to pull them out in order to stitch the worst of the tail and hopes they’ll regrow. Considering that the merman  _ looks _ to be half fish, Cas assumes that the tail works similarly to a fish’s. Except his scales look almost snake-like, which only makes everything more confusing. Though, it seemed as if he might be able to speak and understand English on the beach earlier, when he tried to say something to Cas. Maybe he can ask him about all that once he wakes up.  _ If _ he wakes up, the tiny, nagging voice in the very back of his head adds unhelpfully and Cas is quick to push it right back to where it came from. 

Next thing, though, Cas needs to move the merman from his dinner table and put him - where? It’s evident he’s a marine creature and will therefore need water. He seems to be fine for now, breathing on land, but how much longer can he go on like that? Will he reach a point where it’ll become too much of a strain for him to...

A bark echoes from down the hallway and Cas almost hits himself. Of  _ course _ ! Meg has a pool out back that Cas had built a few years ago after it was clear she wouldn’t stay away. It’s open and leads out to the sea so she can come and go as she pleases. Cas can put the merman in there! That way he’ll stay wet and he’ll be able to be monitored. Also, in that case if Cas can’t be there, Meg can. He’s positive she can somehow understand English and she quite likes him so she’ll probably help.

One thing Cas discovered when he was moving the merman is that he seems to weigh about as much as a normal man, something Cas only knows because of tackling his brothers (read: Gabe), despite his mother’s insistence that it was  _ improper _ and  _ immature _ . He dashes away the thoughts of his family again because right now? He doesn’t need to worry about them on top of everything else. He has a patient that needs his help. 

He carefully edges one arm under the merman’s shoulders, taking special care not to pull on or squish any of the fins that wrap up his shoulder blades, and the other under his tail, where his knees presumably would be, had he been human. He then lifts and, taking his weight on entirely for the first time, Cas realizes that the merman is even lighter than expected. Though, it probably helps that Castiel tries to stay in shape as well and is used to lifting and carrying around various heavy marine animals due to his job.

Cas carefully sets the merman in Meg’s pool, where the sea lion is already swimming in loops and circles. Once the merman is in, Cas decides to let him sink into the water up to his gills, watching in wonder as the small orifices flutter open once they’re completely submerged in the water. The fins, too, seem to open up. They had been flattened close to his body but are now spreading out as well as they can with all the stitches. It doesn’t look like a voluntary movement, more like the fins are relaxing. 

Cas sits next to the rim of the pool, near the merman but not too close in case he wakes up soon. The last thing he’ll need, when waking up disoriented and wounded, is a strange human right in his face. Cas resolves to sit and wait for the merman to wake up. He needs monitoring, after all, so he doesn’t end up floating away and Cas finally allows himself to really look at him, to take in his appearance, no longer searching for injuries that need treatment.

His hair has dried since Cas found him and turned out to be a light brown, almost dirty blond. Cas thinks it could go either way. He’s handsome and Cas wonders if he has a mate at home- Do mermen have homes or mates? Cas files that away into the ever growing pile of questions he wants to ask the merman when he finally wakes up, then is hit with another pang of guilt - this isn’t a research project, this is a  _ patient _ . 

Cas continues scanning him. He has fins in fairly neat lines stretching from his flukes all the way up his tail, with some stretching all the way up to the backs of his shoulders. They’re spiky, but Cas knows they’re flexible. They aren’t smooth like the tangs in his fish tank, they look more like a lionfish’s. Similarly, his dorsal fin is somewhat spiky. He has larger fins on the sides of his tail as well, not as big as the dorsal but bigger than the other small ones. There are also small fins on his elbows, that Cas didn’t even notice at first.

Castiel sits with the merman for hours. He gets up at one point to eat his lunch. Then again to make dinner, which leads to him wondering what mermen eat. He spends a lot of time watching the merman and eventually grabs his glasses and laptop. Making sure to keep the device far enough away from the pool, he settles in to watch a TV show he and Gabe were supposed to be watching together- but with how many times Gabe flies to random locations for work, Cas is sure he’s much farther ahead.

Time flies. It doesn’t feel like it at first, but at one point Cas checks the time and it’s already 7 PM, he left for lunch at 11 this morning. He’s glad he found the merman on his day off, but he’ll have to go back to work at some point. With a shrug, he decides to worry about it later. After a while, Meg hauls herself out of the pool (after sniffing the merman extensively, she seems to have decided he’s safe) and sits next to Cas. She’s small for her age, only just over six feet long and maybe 200 hundred pounds.

It surprises Cas that, to the best of his knowledge, she doesn’t have any babies. He’s known her for nine years, finding her injured when she was just a few months old- she should have had babies by now. But maybe she just kept them hidden from Cas, she  _ is _ a wild animal, after all. It’s just hard to remember that when she flops her head in his lap as he sits cross-legged while watching Netflix. It’s also hard to remember when she lets him pet her head like a dog. He knows that her familiarity with him hasn’t harmed her chances of survival in the wild. She can take care of herself, sometimes disappearing for weeks on end, but she always comes back well-fed and happy.

Cas doesn’t realize that he’s still wearing his coat and t-shirt and jeans, his weekend clothes, until Meg pushes her nose past the lapel of the coat in search of food. She’s probably smelling the faint fishy scent that clings to everything he owns. Similarly, he doesn’t realize he’s fallen asleep until he wakes up to an unfamiliar, deep, slightly hoarse voice.

“Who are you?”

**Author's Note:**

> I know I said I was focusing on Sam's Angels, I'm sorry! 
> 
> This is a collaboration with tumblr user nioellart!
> 
> https://nioellart.tumblr.com/post/636124788528644096/i-had-this-idea-running-around-in-my-head-for-ages
> 
> I've been told that the picture above isn't working so here's the link!


End file.
